Microtiter plates are used for microbiological, cell culture and immunological operations. For instance, microtiter plates are used in the polymerase chain reaction (PCR) and in the culture of microorganisms or cells.
Microtiter plates have a plurality of wells or deepenings for the accommodation of a sample liquid. Such wells are, for example, formed in a plate or have accommodation portions protruding from the bottom side of a plate-shaped cover wall. The cover wall may have side walls projecting towards the downside on the sides thereof. The wells have openings, which can be accessed from the upper side of the plate. The wells are disposed on the points of a raster. The usual microtiter plates have 8×12 arrays of wells provided in rows and columns, but it will be recognized that features of the present disclosure may be provided or used with any number of microtiter plates and/or well arrangements. Microtiter plates with larger arrays, such as 16×24 arrays are also being used increasingly. In most of the current commercially available microtiter plates, the raster distances of the wells correspond to the recommendations of the SBS (Society for biomolecular screening) or the ANSI standards derived therefrom.
In use, it is necessary for the sample in the correct well to be readily determined. Automated robotic systems programmed to move to the appropriate locations as specified by the user have been provided. Automation is costly, presents spatial concerns, and is deemed unnecessary by many. Consequently, much microtiter work is performed manually, creating various opportunities for the introduction of human error. Microtiter plates are often manufactured such that the rows and columns are labeled across the top and side of the plate. For example, the columns may be labeled from 1-12 across the top of a 96 well microtiter plate while the left-hand side is marked A-H. Each individual well can be given a unique identifier (e.g., A1, C5, etc.) and the labels across the top and side aid in identifying the correct well. Nonetheless, in practice human error still occurs because it is difficult to move accurately both down and across the columns and rows since the wells are so closely spaced together. The fact that the microtiter plates are usually made of clear plastic and often contain a clear solution makes it that much more difficult to locate the proper well since there are no guideposts except along the edges of the microtiter plates. Furthermore, microtiter plates are often stored in the cold, often at −80° C., and frost often covers the markings on the edges making accurate reading difficult.
One method used to aid in accurately locating the proper well is to place the microtiter plate on top of a labeled grid. This method includes its own drawbacks. One such problem is that if the grid is not aligned exactly correctly, the wrong labeling will appear beneath each well. It is also easy for the plate to accidentally slide while handling the microtiter plate thereby misaligning the plate with the labeled grid. Furthermore, if the microtiter plate includes an opaque cover or is difficult to see through because of frost or condensation, or if the wells include samples which prevent one from seeing through the microtiter plate.
Another known technique for obtaining accurate readings comprises shining lasers through the wells to correctly mark the desired well. The microtiter plate is placed into a tray connected to a laser and the laser will highlight the correct well. However, if the laser light is from below the microtiter plate, the laser light cannot be seen through an opaque cover if such a cover is used and is difficult to see even if a plastic cover is used. Lasers from above are difficult to build onto the plate and involve aiming by the user for each individual plate and any repeat plates. Plastic strips extending across both the vertical and horizontal planes of the plate (the intersection of which is the desired well) present functional problems such as the inability to fit in a hood and insertion/removal of microtiter plates from the apparatus. Further, these devices can prove expensive both in initial cost and maintenance.
Therefore, there exists a long-felt and unmet need to provide a system and method for accurately working with and recording information related to microtiter plates and their associated wells.